Remove an unnecessary variable projectionScaling from 3 shaders

[zhangyiatmicrosoft]

Launch Checklist

A very minor touch up to remove an unnecessary variable projectionScaling, which was added in PR #4071.

• Confirm your changes do not include backports from Mapbox projects (unless with compliant license) - if you are not sure about this, please ask!
• Briefly describe the changes in this PR.
• Add an entry to CHANGELOG.md under the ## main section.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.80%. Comparing base (26d61c1) to head (79ab843).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4555      +/-   ##
==========================================
- Coverage   87.82%   87.80%   -0.02%     
==========================================
  Files         247      247              
  Lines       33492    33492              
  Branches     2234     2416     +182     
==========================================
- Hits        29413    29409       -4     
+ Misses       3070     3063       -7     
- Partials     1009     1020      +11     

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[HarelM]

I think this is intended to avoid merge conflict with the globe branch, so I would keep it for now until we merge the globe branch.